#include "__imapaccounts.h"
#include "Base64.h"
#include "Exception.h"

#include <cstdio>

namespace jet {

   std::string __imapaccounts::jsonEscape(const std::string &s) {
      std::string out;
      out.reserve(s.size() + 8);
      for (unsigned char c : s) {
         switch (c) {
          case '"': out += "\\\""; break;
          case '\\': out += "\\\\"; break;
          case '\n': out += "\\n"; break;
          case '\r': continue;
          case '\t': out += "\\t"; break;
          default:
            if (c < 0x20) {
               char buf[8];
               snprintf(buf, sizeof(buf), "\\u%04x", c);
               out += buf;
            } else {
               out += (char)c;
            }
         }
      }
      return out;
   }

   static std::string trimWhitespace(const std::string &s) {
      size_t start = s.find_first_not_of(" \t\r\n");
      if (start == std::string::npos)
         return std::string();
      size_t end = s.find_last_not_of(" \t\r\n");
      return s.substr(start, end - start + 1);
   }

   std::vector<std::pair<std::string, std::string>> __imapaccounts::decodeList(const std::string &encodedRaw) {
      std::vector<std::pair<std::string, std::string>> entries;
      coreutils::Base64 base64;
      // The list value round-trips through <eval>/<set> template
      // captures, which include whatever whitespace/newlines surround
      // the tag call in the .jet source - trimming here (rather than
      // insisting every template call site stays whitespace-free) is
      // the robust fix, since a base64 decoder that stops at the first
      // invalid character would otherwise silently truncate to nothing
      // when a stray leading newline precedes real, valid content.
      std::string encoded = trimWhitespace(encodedRaw);
      size_t pos = 0;
      while (pos < encoded.size()) {
         size_t semi = encoded.find(';', pos);
         std::string entry = (semi == std::string::npos) ? encoded.substr(pos) : encoded.substr(pos, semi - pos);
         pos = (semi == std::string::npos) ? encoded.size() : semi + 1;
         entry = trimWhitespace(entry);
         if (entry.empty())
            continue;
         size_t colon = entry.find(':');
         if (colon == std::string::npos)
            continue;
         std::string userB64 = trimWhitespace(entry.substr(0, colon));
         std::string passB64 = trimWhitespace(entry.substr(colon + 1));
         std::string user = base64.decode(userB64).str();
         std::string password = base64.decode(passB64).str();
         entries.push_back(std::make_pair(user, password));
      }
      return entries;
   }

   std::string __imapaccounts::encodeList(const std::vector<std::pair<std::string, std::string>> &entries) {
      coreutils::Base64 base64;
      std::string result;
      for (size_t i = 0; i < entries.size(); i++) {
         if (i > 0)
            result += ";";
         std::string user = entries[i].first;
         std::string password = entries[i].second;
         result += base64.encode(user).str();
         result += ":";
         result += base64.encode(password).str();
      }
      return result;
   }

   __imapaccounts::__imapaccounts(coreutils::ZString &in, coreutils::MString &parentOut, Global &global, Tag *parent, Tag *local) : Tag(in, parentOut, global, parent, local) {

      std::string action = trimWhitespace(resolveKeyword("action").str());
      std::string listStr = resolveKeyword("list").str();
      auto entries = decodeList(listStr);

      if (action == "add") {
         std::string user = trimWhitespace(resolveKeyword("user").str());
         std::string password = trimWhitespace(resolveKeyword("password").str());
         for (size_t i = 0; i < entries.size(); i++) {
            if (entries[i].first == user) {
               entries.erase(entries.begin() + (long)i);
               break;
            }
         }
         entries.push_back(std::make_pair(user, password));
         out = coreutils::MString(encodeList(entries));
      } else if (action == "remove") {
         std::string user = trimWhitespace(resolveKeyword("user").str());
         for (size_t i = 0; i < entries.size(); i++) {
            if (entries[i].first == user) {
               entries.erase(entries.begin() + (long)i);
               break;
            }
         }
         out = coreutils::MString(encodeList(entries));
      } else if (action == "getpassword") {
         std::string user = trimWhitespace(resolveKeyword("user").str());
         std::string password;
         for (size_t i = 0; i < entries.size(); i++) {
            if (entries[i].first == user) {
               password = entries[i].second;
               break;
            }
         }
         out = coreutils::MString(password);
      } else if (action == "firstuser") {
         out = coreutils::MString(entries.empty() ? std::string() : entries[0].first);
      } else if (action == "list") {
         std::string active = resolveKeyword("active").str();
         std::string json = "{\"accounts\":[";
         for (size_t i = 0; i < entries.size(); i++) {
            if (i > 0)
               json += ",";
            json += "\"" + jsonEscape(entries[i].first) + "\"";
         }
         json += "],\"active\":\"" + jsonEscape(active) + "\"}";
         out = coreutils::MString(json);
      } else {
         throw coreutils::Exception("imapaccounts: unknown action \"" + action + "\"", __FILE__, __LINE__, 500);
      }
   }

}